The research will elucidate the mechanism of sperm dysfunction in the case of segregation distorter and it will undertake the examination of the SD system as it exists in nature with an eye to developing methods of population control in insects using meiotic drive. Natural populations will be extensively screened for SD and suppressors of SD to determine whether suppressors are so common in populations having meiotic drive that the seeding technique of population control using meiotic drive would not be effective. Studies on SD-Y translocations in population cages will be carried out to determine the effectiveness of this control scheme and to evaluate the effects of suppressors.